First post here, might as well discuss my observations:
I'm located between Grand Haven, Holland and Allendale. I have Charter digital cable, but I use OTA broadcasts for HD. I'm using a Terk TV35 antenna mounted on a 7ft pole by my front porch with a preamp. It's positioned directly under some power lines, which isn't exactly optimal...
I can easilly recieve WOOD, WXMI, WOTV and WGVU. WZZM is puzzling, it'll show up at 87% strengh, then drop down to nothing, then come back. WTLJ comes in best if I align the antenna perpendicular to their signal. WZPX is sometimes recievable, sometimes not. I've never been able to recieve WWMT.
I noticed that, at the beginning of this month, WGVU started broadcasting in 720p. They still don't carry any HD, but the upconversion looks very nice. I sent them a message in February asking about their DTV plans, and they said that they were going to multicast, and that they planned to broadcast in HD after some "technical issues" were resolved. It's also worth mentioning that audio channel 53 in their broadcast seems to be a simulcast of WGVU-AM.
I'm in a good position to recieve stations from everywhere around Lake Michigan. Stations from South Bend, Chicago and Green Bay come in at around 80% when the antenna is pointed in their direction. Under optimal conditions I can recieve WYIN, WSBT, WSJV, WLS, WMAQ, WTTW, WSNS and WBAY. If it weren't for interference from WXMI, I could almost certainly get WGN in and watch some HD Cubs games.
Small update: After roof mounting my antenna (now about 40 feet in the air), WWMT-DT comes in just fine.